The invention relates to a hand-held high-pressure cleaner provided with an electromotor in a tool-casing, and having a fan provided on its armature shaft, which motor is to drive a pump, the inlet of which can be connected with a source of cleaning fluid, preferably water, and the outlet of which is connected or can be connected with an outlet nozzle, and with at least one handle region for holding the high-pressure cleaner when in operation.
A known high-pressure cleaner of this type (German Utility Model No. 87 13 954) has a tool-casing with a pistol grip, and the electromotor, which drives an axial piston pump arranged in the tool-casing, is located in a region of the tool-casing which projects to the rear.
A problem with this known hand-held high-pressure cleaner is that the electromotor must be positioned in a water-tight casing, because the hand-held high-pressure cleaner is operated in a damp environment and in particular there is always the possibility that either the user will lay the hand tool down on a wet surface or drop it into a wet area, or that it will be operated in an environment where cleaning fluid is also sprayed in the region of the rear part of the tool-casing. If the electromotor is in a water-tight casing it is, however, difficult to cool it sufficiently when it is operating.
It is known in high-pressure cleaners (EP Publication No. 0 177 925) which are operated when stationary for the motor housing to be constructed with double walls and for the cold cleaning fluid to be passed through the annular space thus obtained, which is optionally sub-divided by a helical separating wall, so that the electromotor is cooled in this way. However, only relatively little heat can be dissipated with this cooling system because only the inner surface of the motor housing is available for heat transfer and the stator laminations of the motor are in contact therewith over a large axial area while the windings, which become hot, are situated at a clear distance from the housing wall. For this reason this type of cooling is only suitable for those electromotors which produce little heat relative to their dimensions, for example, induction motors, i.e. electromotors, which are relatively large relative to the power they produce. Such motors are, however, unsuitable for use in hand-held high-pressure cleaners because the resulting dimensions would be too large and the weight too high.
It is the object of the invention to provide a hand-held high-pressure cleaner with a compact and light construction.